1. Field of the Invention
The present invention relates to a display control system having a digital interface.
2. Description of the Prior Art
Systems employing monochrome or color monitors include two kinds of display control systems; one is a display control system having an analog interface, and the other is a display control system with a digital interface.
In either of the above-mentioned display control systems, generally monochrome monitor systems, employing a CRT or liquid crystal, are less expensive than color monitor system. For this reason, the monochrome monitor exists in larger numbers at the present. However, since the color monitor system has also been spreading gradually, software utilizing color display has recently appeared on the market in great numbers.
On the other hand, there are available panel displays which use a liquid crystal, electro-luminescence (EL), plasma or the like. Such panel displays are expected to spread in the future as display devices for hand-held and portable computers. Such panel displays as now used, display only a single color.
In the display system having a digital interface, when software which is intended for a color display may be executed on a conventional system which employs the monochrome monitor. This causes a problem that the display of the software can not be distinguished. This is because the conventional system employing the monochrome monitor can only display in black and white and is incapable of carrying out a color discrimination.
Also, most of the panel displays have a short time of afterglow. Thus, in such panel displays, when a half-brightness display is carried out, there arises a problem that striking flickers are caused to appear.
Furthermore, among the color monitors employed in the display system having digital interface, the color monitors which input a plurality of digital signals are arranged to display only colors that are quite different from natural colors. For example, the color monitor inputting 3 digital signals R, G, B can display only 8 colors, but is unable to display natural colors which are formed by mixing of the RGB.
In addition, in the display systems provided with a digital interface, there is provided a monochrome monitor which is capable of displaying video signals and high-intensity brightness signals (or half-brightness signals). In such a monochrome monitor, a high-intensity brightness white can be displayed in addition to white and black. However, since such a monochrome monitor can display only these three colors and thus four or more colors cannot be displayed by such monitor, it is disadvantageous in that it is not applicable to such a gradation display that includes four or more colors.